Flow through a hexagonal mixing grid with parabolic vanes measured experimentally by PIV in two planes at distances 1 and 5 × the maximum inscribed diameter D at Reynolds number based on D of 1.5⋅104, 3.1⋅104 and 6.2⋅104

Abstract

Particle Image Velocimetry (PIV) method is used to measure the flow through a prototype mixing grid for nuclear reactor. In this preliminary experiment, there are no fuel rods, the grid is empty. We observe the pattern of jets and wakes, which is deformed by the transient flow introduced by the mixing vanes. The flow displays relatively low dependence on Reynolds number and high dependence on the downstream distance. In the contribution, there are shown the spatial maps of mean velocity, turbulence intensity and turbulence flatness.